Recently, a broad outline of human genome analysis has been published and the focus of research is shifting from genome analysis which involves analysis of genome DNA sequence information, to expression (functional) analysis which involves analysis of gene expression. At present, among expressed genes including expression sequence tags (EST), there are few whose function is understood even if the sequence thereof is already known.
In gene expression analysis, techniques for performing analysis with large samples at high speed and good efficiency (high throughput techniques) are required. DNA chip/DNA microarray techniques can provide expression information concerning several tens of thousands of genes in one cell, and are succeeding in effecting high throughput in gene expression analysis experiments.
For example, by using DNA chip/DNA microarray techniques, it is possible to identify genes, the expression level of which changes together with changes in a disease condition. If the expression level of a particular gene correlates highly with the prognosis of a patient, then the expression information concerning this gene can be used as an effective indicator in drug creation.
However, expression information obtainable by DNA chip/DNA microarray techniques does not enable prediction of drug efficacy.